Power amplifier with provisions for varying operating voltage based upon power amplifier output power

ABSTRACT

A power amplifier system is disclosed in which a power amplifier unit and a power amendment unit are provided. An operating voltage is applied to the power amplifier unit. The power management unit monitors the current drawn by the power amplifier unit and generates a control signal based upon the measured current. The operating voltage applied to the power amplifier unit is adjusted based upon the control signal.

CLAIM OF PRIORITY

This application is a division of application Ser. No. 09/792,660, filedFeb. 23, 2001, entitled Power Amplifier With Provisions For VaryingOperating Voltage Based Upon Power Amplifier Output Power, which claimspriority to co-pending U.S. provisional application entitled, “A POWERAMPLIFYING SYSTEM,” having Ser. No. 60/184,682, filed Feb. 24, 2000,which is entirely incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention is generally related to power amplifiers and, moreparticularly, to a system for increasing overall efficiency of a poweramplifier by varying operating voltage applied to a power amplifierbased upon the output power level of the power amplifier.

2. Related Art

In personal communications devices such as cellular telephones, there isa trend toward minimizing size and weight. The size and weight are,however, contingent upon the size and weight of the various componentsthat make up the personal communications device. In short, the smallerthe various components of the personal communications devices, thesmaller the size and overall weight of the personal communicationsdevice itself. Many personal communications devices have an overall sizeand weight which is, to a large degree, dominated by the size and weightof the battery which provides a supply voltage to the personalcommunications device. This is generally due to the fact that consumerswant a personal communications device to have a prolonged operating timeduring usage.

As operating time requirements and power consumption of the personalcommunications device during operations increases, the size of thebattery required to perform under these circumstances will alsoincrease. Thus, where current or power consumption of the personalcommunications devices can be reduced; or the size of components can bereduced; the size of the battery can also be reduced. Alternatively,where the size of the battery remains constant, the operating time ofthe personal communications devices can be increased.

In typical personal communications devices such as, for example,wireless communication devices, efficiency of the device is optimized atmaximum power output without regard to whether or not maximum poweroutput is actually needed. Thus, as the power output of a typicalwireless communications device, for example, drops below the maximumpower (Max Power) output level, the efficiency of the wirelesscommunications device also drops. This does not help to prolong thesupply battery voltage and thus works to limit the operation time to thedevice.

SUMMARY

The invention provides a system for improving the efficiency of a poweramplifier. Briefly described, in architecture, the system can beimplemented as follows: a power amplifier unit and a power amendmentunit are provided. An operating voltage is applied to the poweramplifier unit. The power management unit monitors the current drawn bythe power amplifier unit and generates a control signal based upon themeasured current. The operating voltage applied to the power amplifierunit is adjusted based upon the control signal. Adjustment to theoperating voltage may be made via the power management unit or via anexternal regulator unit.

The invention can also be viewed as providing a method for applying anoperating voltage to a power amplifier unit. In this regard, the methodcan be broadly summarized by the following steps: An operating voltageVbb is applied to a power amplifier unit 120. The current drawn by thepower amplifier unit is then monitored and the current flow is measured.A current flow signal is generated and output based upon the measuredcurrent flow. The current flow signal is then received by a controllerthat generates a control signal based upon the current flow signal. Thecontrol signal is then output to a voltage regulator, which then adjuststhe operating voltage applied to the power amplifier unit based upon thecontrol signal.

Other systems, methods, features, and advantages of the invention willbe or become apparent to one with skill in the art upon examination ofthe following figures and detailed description. It is intended that allsuch additional systems, methods, features, and advantages be includedwithin this description, be within the scope of the invention, and beprotected by the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The components in the drawings are not necessarily to scale, emphasisinstead being placed upon clearly illustrating the principles of theinvention. In the figures, like reference numerals designatecorresponding parts throughout the different views.

FIG. 1 is a block diagram illustrating a power amplifier control system.

FIG. 2 is a block diagram illustrating another embodiment of a poweramplifier control system.

FIG. 3 is a block diagram illustrating a bypass unit 190.

FIG. 4 is a block diagram illustrating another embodiment of a poweramplifier control system.

FIG. 5 is a block diagram illustrating the power amplifier controlsystem in FIG. 1.

FIG. 6 is diagram detailing one configuration for determining poweramplifier unit power consumption.

FIG. 7 is a further diagram detailing a configuration for determiningpower amplifier unit power consumption.

FIG. 8 is a flowchart illustrating a method of applying an operatingvoltage to a power amplifier unit of a personal communications device.

FIG. 9 is a block diagram illustrating a look up table (“LUT”) forcorrelating current flow values with control signal values.

FIG. 10 is a flowchart illustrating another method of applying anoperating voltage to a power amplifier unit of a personal communicationsdevice.

DETAILED DESCRIPTION

The personal communications device of the invention provides for reducedpower consumption by varying the operating voltage that is applied tothe circuitry of the personal communications device. More particularly,the operating voltage applied to the power amplification unit of thepersonal communications device is varied based upon the measured outputpower level of power amplifier.

FIG. 1 illustrates one embodiment of a personal communications device100. A power amplifier unit 120 and power management unit 110 areprovided. Power amplifier unit 120 includes a power amplifier 150. Poweramplifier 150 includes an input 151 for receiving a radio frequency (RF)signal and an output 152 for outputting an amplified RF signal.

Power management unit 110 includes a current meter 180, a controller 170and a regulator 160. An operating voltage Vbb is provided to the poweramplifier 150 by voltage regulator 160. Switching regulator 160 receivesa supply voltage Vcc of a predetermined voltage level and outputs anoperating voltage Vbb to the power amplifier 150.

A current meter 180 monitors (measures) the DC current flow of theoperating voltage supply Vbb provided to the power amplifier unit 120and generates a current flow indicator signal X representative of themeasured DC current flow of the operating voltage supply applied to thepower amplifier unit 120. This current flow indicator signal X isprovided to a controller 170. By monitoring the current Ibb drawn by thepower amplifier unit 120, it is possible to determine the power outputof the power amplifier unit 120. In this way, for a given current flowindicator signal X, there is a corresponding output power level at whichthe power amplifier unit 120 operates. By monitoring the current Ibbdrawn by the power amplifier unit 120, it is possible to determine thepower output of the power amplifier unit 120. In this way, the currentsignal X can also be considered indicative of the power output level ofthe power amplifier unit 120.

Controller 170 controls switching regulator 160 via providing a controlsignal Z. Control signal Z is generated by the controller 170 based uponthe current flow indicated by the current flow indicator signal X.

The operating voltage Vbb output by the regulator 160 to the poweramplifier 150 is determined in accordance with the control signal Zoutput by controller 170.

The operating voltage Vbb may be selected from any one of apredetermined number of voltage levels. For example, Vbb may be between0 volts and the supply voltage Vcc. Further, Vbb may be linearlyvariable between, for example, 0 volts and Vcc, in accordance with thecontrol signal Z.

FIG. 2 shows a block diagram illustrating a power amplifier controlsystem. A power amplifier unit 120 is provided and includes a poweramplifier 150. Power amplifier 150 includes an input 151 for receiving aradio frequency (RF) signal and an output 152 for outputting anamplified RF signal.

A power management unit 110 is provided. Power management unit 110includes a power meter 180, a controller 170, a regulator 160 and abypass switch 190. The output 152 of power amplifier 150 is connected toa power meter 180.

Power meter 180 monitors (measures) the power at the output of the poweramplifier 152 of power amplifier 150 and generates a power outputindicator signal X.

This power output indicator signal X is then provided to the controller170. Controller 170 receives the signal X and in turn, generates acontrol signal Z and a bypass signal Z′. Control signal Z variesdepending upon the value of the power output indicator signal X. Controlsignal Z′ also varies depending upon the value of the power outputindicator signal X. Controller 170 controls regulator 160 via providinga control signal Z.

Regulator 160 receives a supply voltage Vcc of a predetermined voltagelevel and outputs an operating voltage Vbb to the power amplifier 150.The operating voltage Vbb output to the power amplifier 150 isdetermined in accordance with the control signal Z and bypass signal Z′output by controller 170. The operating voltage Vbb may be any one of apredetermined number of voltage levels between, for example, 0 volts andVcc. Further, the operating voltage Vbb may be linearly variablebetween, for example, 0 volts and Vcc, in accordance with the controlsignal Z. In a preferred embodiment, the regulator 160 outputs aoperating voltage Vbb, to the power amplifier unit 120, of approximately2.2 volts (+2.2 VDC) where the power output indicator signal X indicatesthat the power amplifier unit 120 is operating at a power level of lessthan, for example, 22 dBM.

Bypass switch 190 is connected in parallel with the regulator 160 andreceives input of the supply voltage Vcc. Bypass switch 190 iscontrolled by bypass signal Z′, that causes the bypass switch 190 toopen or close. When bypass switch 190 is closed, the operating voltageVbb applied to the power amplifier unit 120 preferably goes to theoperating supply voltage Vcc. In a preferred embodiment, bypass switch190 is closed when the power output indicator signal X indicates thatthe power amplifier unit 120 is consuming, or operating at, a high powerlevel. For example, where the power amplifier unit is consuming a powerlevel greater than 22-24 dBm, the bypass signal Z′ may be output by thecontroller 170 to close the bypass switch 190. Once bypass switch 190 isclosed, the operating voltage Vbb applied to the power amplifier unit120 is effectively taken to a level approximately equal to the supplyvoltage Vcc.

FIG. 3 is a more detailed illustration of bypass unit 190. It can beseen that bypass unit 190 includes a switch 302 that is actuated by thebypass signal Z′. Bypass unit 190 may be configured, for example, byusing transistor (semiconductor) switches for switch 302. Further,bypass unit 190 may be configured using electrically actuated mechanicalswitching devices as switch 302.

FIG. 4 is a block diagram illustrating another embodiment of a poweramplifier control system. A power amplifier unit 120 and powermanagement unit 110 are provided. Power amplifier unit 120 includes apower amplifier 150. Power amplifier 150 includes an input 151 forreceiving a radio frequency (RF) signal and an output 152 for outputtingan amplified RF signal

In addition, the power amplifier 150 of power amplifier unit 120 mayprovide for enable input (enable pin) 453 that is capable of turning onand off the power amplifier 150 by application of a predeterminedsignal. This signal may be, for example, a complementary metal oxide(CMOS) or transistor transistor logic (TTL) compliant/compatible signal.The power amplifier unit 120 may also provide for a reference voltageinput (reference voltage pin) 454, which may be used to provide areference voltage Vref to control the operation of the power amplifier150. The reference voltage Vref may also be used to sense the outputpower of the power amplifier unit 120.

Power management unit 110 includes a current meter 180, a controller170, a bypass switch 190, and a reference voltage regulator 165. Anoperating voltage Vbb is provided to the power amplifier 150 by voltagesupply regulator 160. An operating voltage, Vref is supplied to thepower amplifier 150 by the reference voltage regulator 165. Currentmeter 180 monitors the current flow of the line providing the referencevoltage Vref from the reference voltage regulator to the power amplifier150 and generates a current indicator signal X that is applied to thecontroller 170. In turn, controller 170 outputs a control signal Z tothe voltage regulator 160. Voltage regulator 160 receives a supplyvoltage Vcc of a predetermined voltage level and outputs an operatingvoltage Vbb to the power amplifier 150 in accordance with the controlsignal Z received from the controller 170.

The current meter 180 monitors (measures) the DC current flow of thereference voltage supply Vref provided to the power amplifier unit 120and generates a current flow indicator signal X representative of themeasured DC current flow of the operating voltage supply applied to thepower amplifier unit 120. This current flow indicator signal X isprovided to a controller 170. By monitoring the current Ivr drawn by thepower amplifier unit 120, it is possible to determine the power outputof the power amplifier unit 120. In this way, for a given current flowindicator signal X, there is a corresponding output power level at whichthe power amplifier unit 120 operates. By monitoring the current Ivrdrawn by the power amplifier unit 120, it is possible to determine thepower output of the power amplifier unit 120. In this way, the currentsignal X can also be considered indicative of the power output level ofthe power amplifier unit 120.

In one embodiment, controller 170 controls switching regulator 160 viacontrol signal Z. Control signal Z may be generated by the controller170 based upon the current flow indicated by the current flow indicatorsignal X.

The operating voltage Vbb output by the voltage regulator 160 to thepower amplifier 150 is determined in accordance with the control signalZ output by controller 170. The operating voltage Vbb may be selectedfrom any one of a predetermined number of voltage levels. Vbb may bebetween, for example, 0 volts and the supply voltage, Vcc. Further, Vbbmay be linearly variable between, for example, 0 volts and Vcc, inaccordance with the control signal Z. In a further embodiment, anexternal control signal M may be applied to the controller 170. In turn,the controller 170 generates the control signal Z in accordance with theexternal control signal M. Control signal M may be, for example, a logicsignal generated by an external source associated with the system 100.

FIG. 5 shows a block diagram illustrating the power amplifier controlsystem in FIG. 1. In this example, power amplifier unit 120 is amulti-stage power amplifier unit. Power amplifier unit 120 includes aninput matching unit 552 for matching the impedance of the input 151 to apower amplifier 554. The output of power amplifier 554 is connected toan interstage matching unit 556. Interstage matching unit 556 matchesthe output impedance of power amplifier 554 to the input impedance ofpower amplifier 558. An output matching unit 560 is provided to matchthe output impedance of power amplifier 558 to the output 152. The biascontrol network 520 is capable of powering on (enabling) the amplifierunit 120 by using the reference current Ivr from the power managementcircuit 110 or by applying an appropriate enable signal to an enable pin553 that may be optionally provided. Bias control 520 is preferablyconfigured as a part of the power amplifier unit 120.

Power management unit 110 includes a current meter 180 and controller170. Current meter 580 measures the current Ibb drawn by the poweramplifier unit 120. A current signal X is generated to indicate thecurrent Ibb drawn by the power amplifier unit 120.

Alternatively, current meter 580 may be configured to measure thecurrent Ivr drawn by the power amplifier unit 120 as shown in FIG. 6. Inthis case, a current signal X is generated to indicate the current Ivrdrawn by the power amplifier unit 120.

For a given current flow indicator signal X, there is a correspondingoutput power level at which the power amplifier unit 120 operates. Bymonitoring the current Ibb drawn by the power amplifier unit 120, it ispossible to determine the power output of the power amplifier unit 120.In this way, the current flow indicator signal X can also be consideredindicative of the power output level of the power amplifier unit 120.

The current flow indicator signal X is provided to the controller 170.Controller 170 receives the current flow indicator signal X and in turn,generates a control signal Z and bypass signal Z′. Control signal Z andbypass signal Z′ varies depending upon the value of the current flowindicator signal X. This control signal Z and the bypass signal Z′ areeach applied to the base of field effect transistors (FET) 568 and 570,respectively. FET 570 is controlled by control signal Z and is connectedbetween the supply voltage Vcc and an inductor 365. FET 570 iscontrolled by bypass signal Z′ and is connected between the supplyvoltage Vcc and the output of the inductor 565. The control signal Zcauses the FET 568 to adjust current flow through the inductor 565 andin turn causes the operating voltage Vbb to be adjusted upward ordownward as required. The control signal Z′ causes the FET 570 to turnon completely so as to provide supply voltage Vcc directly to the poweramplifier unit 120, thus greatly reducing the power losses between Vccand the power amplifier unit 120 under high current operation.

Controller 170 also provides a reference voltage Vref to the biascontroller 520. The reference voltage Vref is preferably independent ofthe operating voltage Vbb. In a preferred embodiment, reference voltageVref is three volts (+3.0 VDC).

In one embodiment of the personal communications device 100, theoperating voltage Vbb is, for example, between +3.0 and 4.2 volts DC(+3.0 VDC-+4.2 VDC). Further, where the current monitor 180 detects acurrent flow Ibb that corresponds to an amplifier power output of onemilliwatt (1 mW), the controller 170 outputs a control signal Z andbypass signal Z′ that causes the operating voltage Vbb to be adjusted to+0.6 volts DC (+0.6 VDC), thus greatly increasing the efficiency of thepower amplifier unit 120.

The power amplifier unit 120 may be fabricated using gallium arsenide(GaAs) semiconductor technology. The power management unit 110 may alsobe fabricated using complementary metal oxide semiconductor (CMOS)technology. Further, both power amplifier unit 120 and power managementunit 110 may be fabricated on a single integrated circuit. Theintegrated circuit may be configured in a package having a length of,for example, but not limited to, between 8.25-8.51 millimeters (mm); anda width of between 8.26-8.51 millimeters(mm). Alternatively, poweramplifier unit 120 and power management unit 110 may be fabricated onseparate integrated circuits.

FIG. 7 shows a block diagram illustrating another embodiment of a poweramplifier control system. In this embodiment, a regulator 160 isprovided to supply the power amplifier unit 120 with an operatingvoltage Vbb. In this embodiment regulator 160 is external to the powermanagement unit 110 and is controlled by a control signal Z from thecontroller 170. This embodiment provides for a personal communicationsdevice 100 in which the power amplifier unit 120 and power managementunit 110 may be configured on a single integrated circuit, as discussedabove with regard to FIG. 4, and utilized in conjunction with a separatevoltage regulator. Voltage regulator 160 may be, for example, aswitching voltage regulator.

FIG. 8 is a flowchart illustrating a method of providing an operatingvoltage to a power amplifier unit. An operating voltage Vbb is appliedto the power amplifier unit 120 (802). The current drawn by the poweramplifier unit 120 is then monitored by, for example, a current meter180, to measure the current flow Ibb (or, alternatively, the currentflow Ivr) (804). A current flow signal is generated by the current meter180 and output to a controller 170 based upon the measured current flow(806). The current flow signal is then received by a controller 170 thatthen generates a control signal based upon the current flow signal(808). The control signal is then output to a regulator 160 that thenadjusts the operating voltage applied to the power amplifier unit 120based upon the control signal (810).

FIG. 9 illustrates an embodiment of a personal communications device inwhich a lookup table (LUT) 910 is incorporated and utilized forcorrelating a measured current value with a corresponding control value(control signal value). LUT 910 may be incorporated as a part of thepower management unit 110. Alternatively, it may be external to thepower management unit 110. A power amplifier unit 120 and powermanagement unit 110 are provided. Power amplifier unit 120 includes apower amplifier 150. Power amplifier 150 includes an input 151 forreceiving a radio frequency (RF) signal and an output 152 for outputtingan amplified RF signal.

Power management unit 110 includes a current meter 180, a controller 170and a regulator 160. An operating voltage Vbb is provided to the poweramplifier 150 by voltage regulator 160. Regulator 160 receives a supplyvoltage Vcc of a predetermined voltage level and outputs an operatingvoltage Vbb to the power amplifier 150.

A current meter 180 monitors (measures) the DC current flow Ibb of theoperating voltage supply Vbb provided to the power amplifier unit 120and generates a current flow indicator signal X representative of themeasured DC current flow of the operating voltage supply applied to thepower amplifier unit 120. This current flow indicator signal X isprovided to a controller 170. Controller 170 accesses and refers to theLUT 910 to obtain a control signal value corresponding to the currentflow indicator signal X. The control signal value Z is then output tothe regulator 160. In turn regulator 160 adjusts the operating voltageVbb output by the regulator 160 and applied to the power amplifier unit120 based upon the control signal Z value retrieved from LUT 910.

The operating voltage Vbb may be selected from any one of apredetermined number of voltage levels. Vbb may be between, for example,0 volts and the supply voltage, Vcc. Further, Vbb may be linearlyvariable between, for example, 0 volts and Vcc, in accordance with thecontrol signal Z.

FIG. 10 is a flowchart illustrating a further method of providing anoperating voltage to a power amplifier unit. It can be seen that anoperating voltage Vbb is applied to the power amplifier unit 120 (1002).The current drawn by the power amplifier unit 120 is then monitored by,for example, a current meter 180, to measure the current flow Ibb (or,alternatively, the current flow Ivr) (1004). A current flow signal isgenerated by the current meter 180 and output to a controller 170 basedupon the measured current flow (1006). The controller 170 refers to alook up table (LUT) to determine a value that corresponds to themeasured current flow (1008). The controller 170 that then outputs acontrol signal based upon the corresponding value (1010). The controlsignal is then output to a regulator 160 that then adjusts the operatingvoltage applied to the power amplifier unit 120 based upon the controlsignal (1012).

The flow charts of FIG. 8 and FIG. 10 show the architecture,functionality, and operation of a possible implementation of thesoftware capable of carrying out the methodology set out therein. Inthis regard, each block represents a module, segment, or portion ofcode, which comprises one or more executable instructions forimplementing the specified logical function(s). It should also be notedthat in some alternative implementations, the functions noted in theblocks may occur out of the order noted in the flowcharts of FIG. 8 andFIG. 10. For example, two blocks shown in succession in the flowchartsmay in fact be executed substantially concurrently or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved.

While various embodiments of the invention have been described, it willbe apparent to those of ordinary skill in the art that many moreembodiments and implementations are possible that are within the scopeof this invention.

What is claimed:
 1. A personal communications device comprising: asupply input for receiving a power supply voltage; a power amplifierunit; a controller; a voltage regulator for receiving a power supplyvoltage input via the supply input and outputting a operating voltagesupply to the power amplifier; a current monitor for measuring thecurrent flow of the operating voltage supply output to the poweramplifier unit and outputting a current indicator signal; the controllerreceives the current indicator signal and generates a control signal inaccordance with the current indicator signal; and the voltage regulatoradjusts the operating voltage supply in accordance with the controlsignal.
 2. The personal communications device of claim 1, wherein thepower amplifier unit comprises a two stage power amplifier.
 3. Thepersonal communications device of claim 1, further comprising a mobiletelephone.
 4. The personal communications device of claim 3, wherein themobile telephone comprises a code division multiple access (CDMA)compliant mobile telephone.
 5. The personal communications device ofclaim 3, wherein the mobile telephone comprises a time division multipleaccess (TDMA) compliant mobile telephone.
 6. A personal communicationsdevice comprising: a supply input for receiving a power supply voltage;a power amplifier unit; a regulator for receiving a power supply voltageinput via the supply input and outputting a operating voltage supply tothe power amplifier unit; the power amplifier unit further comprises acurrent monitor for measuring the current flow of the operating voltagesupply output to the power amplifier unit and outputting a currentindicator signal in accordance therewith; the power amplifier unitfurther comprises a controller for receiving the current indicatorsignal and generating a control signal in accordance with the currentindicator signal; and the voltage regulator adjusts the operatingvoltage supply in accordance with the control signal.
 7. The personalcommunications device of claim 6, wherein the power amplifier unitcomprises a radio frequency power amplifier.
 8. The personalcommunications device of claim 6, wherein the power amplifier unitcomprises a multi-stage radio frequency power amplifier.
 9. The personalcommunications device of claim 6, wherein the power amplifier unitcomprises an integrated circuit.
 10. The personal communications deviceof claim 9, wherein the integrated circuit comprises a gallium arsenide(GaAs) integrated circuit.
 11. A power amplifier unit comprising: apower amplifier; an input for receiving an operating supply voltage topower the power amplifier; a current monitor for monitoring the currentflow of the operating supply voltage and outputting a current flowsignal based upon the measured current flow; a look-up table (LUT) forcorrelating the measured current flow with the current flow signal; anda controller for outputting a control signal in accordance with the LUTand the current flow signal.
 12. The power amplifier unit of claim 11,wherein the power amplifier comprises a radio frequency power amplifier.13. The power amplifier unit of claim 12, wherein the power amplifiercomprises a multi-stage power amplifier.
 14. The power amplifier unit ofclaim 11, wherein the power amplifier unit further comprises anintegrated circuit.
 15. The power amplifier unit of claim 11, whereinthe integrated circuit comprises a complementary metal oxide (CMOS)semiconductor.
 16. A power amplifier unit comprising: a power amplifier;an input for receiving a supply voltage; a current monitor formonitoring the current flow of the operating supply voltage andoutputting a current flow signal based upon the measured current flow;controller for outputting a control signal based upon the current flowsignal; and regulator for outputting an operating voltage to the poweramplifier based upon the current flow signal.
 17. The power amplifierunit of claim 16, wherein the power amplifier comprises a radiofrequency power amplifier.
 18. The power amplifier unit of claim 16,wherein the power amplifier comprises a multi-stage power amplifier. 19.The power amplifier unit of claim 16, wherein the power amplifier unitfurther comprises an integrated circuit.
 20. The power amplifier unit ofclaim 15, wherein the power amplifier comprises a gallium arsenide(GaAs) transistor.
 21. The power amplifier unit of claim 16, wherein thecontroller comprises a complementary metal oxide (CMOS) transistor. 22.The power amplifier unit of claim 16, wherein the regulator outputs anoperating voltage of +1.6 volts DC where the current flow signalindicates the power amplifier is consuming 1 milliwatt of power.
 23. Apersonal communications device comprising: a power amplifier unit; apower management unit; the power management unit comprises an input forreceiving a supply voltage; a current monitor for monitoring the currentflow of an operating supply voltage applied to the power amplifier unitand outputting a current flow signal based upon the measured currentflow; controller for outputting a control signal based upon the currentflow signal; and regulator for outputting an operating voltage to thepower amplifier unit based upon the current flow signal.
 24. Thepersonal communications device of claim 23, further comprising a bypassunit for selectively providing the supply voltage to the power amplifierunit as the operating voltage.
 25. The personal communications device ofclaim 23, wherein the power amplifier comprises a radio frequency poweramplifier.
 26. The personal communications device of claim 25, whereinthe power amplifier comprises a multi-stage power amplifier.
 27. Thepersonal communications device unit of claim 23, wherein the poweramplifier unit comprises an integrated circuit.
 28. The personalcommunications device unit of claim 27, wherein the integrated circuitcomprises a gallium arsenide transistor.
 29. The personal communicationsdevice of claim 27, wherein the power management unit comprises acomplementary metal oxide (CMOS) transistor.
 30. The personalcommunications device of claim 29, wherein the power management unit andthe power amplifier unit are contained on a single integrated circuit,comprises a complementary metal oxide (CMOS) transistor.
 31. Thepersonal communications device of claim 23, wherein the regulatoroutputs an operating voltage of +1.6 volts DC where the current flowsignal indicates the power amplifier is consuming 1 milliwatt of power.32. A method of applying a power supply voltage to a power amplifierunit comprising the steps of: applying a operating voltage to a poweramplifier unit; measuring the current drawn by the power amplifier unit;generating a current flow signal indicative of the current drawn by thepower amplifier unit; generating a control signal based upon the currentflow signal; and adjusting the operating voltage based upon the controlsignal.
 33. The method of claim 32, further comprising the step ofadjusting the operating voltage to the supply voltage level where thecurrent flow signal indicates the power amplifier unit is operating at apower level greater than 22 dBm.
 34. The method of claim 32, furthercomprising the step of adjusting the operating voltage to +2.2 volts DC(+2.2 VDC) where the current flow signal indicates the power amplifierunit is operating at a power level of less than 22 dBm.
 35. A method ofapplying a power supply voltage to a power amplifier unit comprising thesteps of: applying a operating voltage to a power amplifier unit;measuring the current drawn by the power amplifier unit; generating acurrent flow signal indicative of the current drawn by the poweramplifier unit; looking up a value corresponding to the current flowsignal; generating a control signal based upon the corresponding value;and adjusting the operating voltage based upon the control signal.
 36. Apersonal communications device comprising: a power amplifier means; apower management means; the power management means comprises an inputfor receiving a supply voltage; a means for monitoring the current flowof an operating supply voltage applied to the power amplifier unit andoutputting a current flow signal based upon the measured current flow;means for outputting a control signal based upon the current flowsignal; and means for outputting an operating voltage to the poweramplifier unit based upon the current flow signal.
 37. The personalcommunications device of claim 1, further comprising a look-up table(LUT) for correlating the measured current flow with the currentindicator signal.
 38. The personal communications device of claim 1,further comprising a bypass switch that communicates with the controllerto determine applying the power supply voltage to the power amplifierunit through the bypass switch.
 39. The personal communications deviceof claim 6, further comprising a look-up table (LUT) for correlating themeasured current flow with the current indicator signal.
 40. Thepersonal communications device of claim 6, further comprising a bypassswitch that communicates with the controller to determine applying thepower supply voltage to the power amplifier unit through the bypassswitch.
 41. The personal communications device of claim 16, furthercomprising a look-up table (LUT) for correlating the measured currentflow with the current indicator signal.
 42. The personal communicationsdevice of claim 16, further comprising a bypass switch that communicateswith the controller to determine applying the power supply voltage tothe power amplifier unit through the bypass switch.
 43. The personalcommunications device of claim 23, further comprising a look-up table(LUT) for correlating the measured current flow with the currentindicator signal.
 44. The personal communications device of claim 23,further comprising a bypass switch that communicates with the controllerto determine applying the power supply voltage to the power amplifierunit through the bypass switch.
 45. The power amplifier unit of claim11, further comprising a bypass which communicates with a controller todetermine applying the supply voltage to the power amplifier through thebypass switch.
 46. The method of claim 32, further comprising applyingthe power supply voltage to the power amplifier unit through a bypassswitch.
 47. The method of claim 35, further comprising applying thepower supply voltage to the power amplifier unit through a bypassswitch.